In automobile headlamps and other vehicular lighting fixtures, fog occurs when high-humidity air enters the light chamber, the lens is cooled by outside air, rainfall or the like, and moisture condenses on the inner surface. This reduces the brightness of the vehicular lamp, and can also make the lens less attractive, causing user dissatisfaction. Anti-fog coatings that are coated on the areas where fog occurs are known as a means of preventing such fogging of the lens.
The applicants in this case have already proposed a heat-cured anti-fog coating composition such as the following (see Patent Document 1). This heat-cured anti-fog coating composition contains a monomer having a cross-linkable functional group that is either a N-methylol group, a N-methylol ether group or a hydroxyl group, and a block or graft copolymer consisting of a hydrophilic polymer part formed from a hydrophilic monomer and a lower alkyl(meth)acrylate and a hydrophobic polymer part formed from a vinyl monomer having a sulfonic acid, carboxyl or phosphoric acid group and a lower alkyl(meth)acrylate. With this anti-fog coating composition, it is possible to form a coating film whereby excellent anti-fog properties and adhesiveness are maintained in high-temperature environments.    Patent Document 1: Japanese Patent Application Laid-open No. H6-212146 (page 2, page 3, pages 14 to 17)